Process for the production of salts from brines and solutions



wubmzwma 4 Sheets-Sheet l INVENTOR o. V. MARTIN Filed y 19. 1926zuwzuozou PROCESS FOR THE PH'ODUCTIQN' OF SALTS FROM BRINES ANDSOLUTIONS Jan. 31

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ATTORNEYS WITNESSES Jan. 31, 1923. 1,657,633 I o. v. MARTIN PROCESS FORTHE PRODUCTION OF SALTS FROM BRINES AND SOLUTIONS Filed May 19. 1926 4Sheets-Sheet 2 WITNESSES INVENTOR ATTORNEYS Jan. 31, 1928.

O. V. MARTIN PROCESS FOR THE PRODUCTION OF SALTS FROM BHINES ANDSOLUTIONS 4 Sheets-Sheet 5 Filed y 19. 1926 lulu".

INVENTOR Otto K fi/arh'n,

ATTORNEYS Jan. 31, 1928.

O. V. MARTIN PROCESS FOR REPRODUCTION OF SALTS FROM BRINES AND SOLUTIONSFiled May 19. 1926 4 Sheets-Sheet 4 WITNESSES NVENTOR 0M0 V/l/arh'v,

BY E6 ATTORNEYS Patented Jan. 31, 1928.

UNITED STATES 1,657,633 PATENT OFFICE.

OTTO V. MARTIN, OF SAND SPRINGS, OKLAHOMA, ASSIGNOR TO THE MABTIN-COLVIN(10., A CORPORATION OF ILLINOIS.

PROCESS FOR THE PRODUCTION'OF SALTS FROM BRINES AND SOLUTIONS.

Application filed May 19,

This invention relates to a process and an apparatus for manufacturingsalts from solution.

It has been proposed to evaporate brine in -,vacuum tanks and in whichexternal heat is applied for causing vaporization of the brine under lowpressures. It is necessary in such instance to produce steam for heatingpurposes and to require the use of av vacuum pump. lVhile this method ofrecovering salts from brine is effective, nevertheless it is expensive.

It also has been proposed either to em ploy open air or solar pans forcausing evaporation of the brine or salt solution or the salt solutionhas been sprayed above an open tank in a closed room in which the air iseither at atmospheric temperature or heated above the same.

This process and apparatus provides an economical recovery of inorganicsalts or organic salts or other materials which have either gone intosolution or are suspended in solution inasmuch as it utilizes the heatunits of exhaust turbine steam when the steam is condensed Withoutappreciably lowering the temperature of the condensate.

In order to fully appreciate conditions under which the process isoperated it Will be necessary to set forth briefly the sequence ofcoordinated steps. In industrial plants the steam is passed. throughcondensers cooled by running water which, in turn, is cooled by sprayponds in the open air. The latent heat freed in the condensation of thesteam which is transmitted to the cooling water is dissipated to theatmosphere and this dissipated heat represents considerable loss in fuelto the plant. This is particularly true of plants in which steamturbines are employed for operating generators, the steam from suchturbines being exhausted upon surface condensers upon which a highvacuum is drawn so that the pressure in the condenser is approximatelyzero absolute. 1n

a. plant Where steam is generated and utilized in a vacuum turbine theWater enters the boilers at approximately 80 F. This Water is thenconverted into steam at a temperature approximately 370 F. (a pressureof about 190 lbs). It requires one B. t. u. to raise 1 lb. of Water 1F.. therefore it would require 290 B. t. u.s to raise 1 lb. from 80 F.to 370 F. But in order to overcome the tendency of cohesion of the t1926. Serial No. 110,219.

molecules and change the water to steam an additional 970 B t. u.s isrequired. From the boilers the steam is directed into a turbine'wherethe expansion and decrease in pressure of this steam is used to operatethe turbine. The steam passing through the turbine is then conductedthrough a surface condenser. A vacuum pump operating upon the condenserreduces the pressure in the final stage of the turbine to approximately0 absolute scale. At-this point Water has a boiling temperatureapproximating 80 F.

By this mechanical arrangement I am enabled to regain most of the 290 B.t. u.s from each pound of steam. The steam at this stage still containsthe heat of vaporization (970 B. t. u.s approximately per pound).

Under normal operating conditions about 100 lbs. of cooling Water iscirculated through the condenser 'foreach pound of steam. This coolingwater takes the heat of vaporization from the steam and converts it intoWater Without appreciably changing its temperature. The cooling wa teris then conveyed through a spray system Where the heat is dissipatedwhile the condensed steam is returned through prehea-ters to the boilerfor regeneration. In addition, the latent heat of vaporization is lost.

The present invention contemplates, in those plants which are so happilysituated as to have crystalloid substances in solution in the coolingfluid, the utilization of the heat otherwise Wasted in the coolingmedium for the recovery of these substances in crystalline form, and inso doing the present invention proposes the practice of a method andapparatus different and more eflicient than that employed in plantsWhose sole or main function is the recovery of crystalline solids.

In plants of the latter type where evaporation or crystallization isessential for the recovery of inorganic salts, organic compounds orfinely divided materials in sus pension in the liquid, vacuumevaporators are employed in Which'steam forms the heating element, and avacuum is drawn so that the solutions boil at a low temperature.

evaporators are usually weak and in order to bring such solutions totheir final state of concentration or dryness a great deal of time andexpense is required.

It is an object of the present invention to utilize the latent heat ofthe steam at as near zero pressure absolute as it is possible to obtainwithout appreciably lowering the temperature of the condensate as saidcondensate passes thru a surface condenser, for raising the temperatureof weak or saturated solutions used as the condensing medium toapproximately the atmospheric temperature of the air for a particularlocality so that when the heated solution is sprayed as a mist into theatmosphere the solutions will be evaporated rapidly and thusconcentrated. The process is continuous and this is true whether theapparatus constructed according to the principles of the presentinvention is coordinated with a condenser of a steam turbine or a vacuumevaporator.

Another object of the invention is the provision of a process forrecovering salts from solution and in which the brine is reduced tosuper-saturation by spraying brine which has received heat units fromsteam passing through a condenser and in which the brine, is employed asa cooling liquid for the steam, the temperature of the brine beingreduced by spraying to approximately the dew point so that moisture isremoved between points where the mist is created and the level ofsolution in the tank with the subsequent concentration of the solution.

A further object of the invention is the provision of a continuousprocess for recovering salts from solution and in which the solution ispassed through a surface condenser thereby utilizing the latent heatfrom the condensate to increase the temperature of the solution slightlyabove atmospheric temperature and converting the heated brine into amist over a tank exposed to the atmosphere thereby reducing thetemperature of the brine to approximately the dew point so that moistureis evaporated and the brine concentrated, then returning theconcentrated brine to the condenser for absorbing heat units from thesurface condenser while at the same time supplying a fresh charge ofbrine to the concentrai ed brine on its path through the condenser tonot only maintain the normal level of the brine in the tank but forpreventing formation of crystals along the path of the brine to saidcondenser.

A still further object of the invention is the provision of a processand apparatus for recovering salts from solutions in which the latentheat of a condensate passing through a condenser is utilized to increasethe temperature of the solution slightly above atmospheric temperaturewithout decreasing the temperture of the condensate appreciably belowits boiling point, then converting the heated brine into a mist andexposing the same to the atmosphere, thereby re ducing the temperatureof the brine to approximately the dew point while controlling the extentof fall of the mist and varying the direction of its fall for regulatingthe size of the crystals which crytallize from the brine.

This invention will be best understood from a consideration of thefollowing 'detailed description, in view of the accompanying drawingsforming a part of the specification; nevertheless it is to be understoodthat the invention is not confined to the disclosure, being susceptibleof such changes and modifications which shall define no materialdeparture from the salient features of the invention as expressed in theappended claims.

In the drawings:

Figure 1 shows more orless diagrammatically an arrangement for carryingout my process. 1

Figure 2 is a transverse vertical section of the open evaporating brinetank employed in the arrangement.

Figure 3 is a fragmentary longitudinal section of a portion of the tankshowing the construction of the piping for withdrawing brine from thetank.

Figure 4 is a plan view of the "open brine tank.

Referring more particularly to the drawings. 1O designates asteamturbine which may be of the Allis-Chalmers type connected by means of apipe 11 with a surface condenser 12. This condenser is connected with avacuum pump 13 which is connected by means of a pipe 14 with the surfacecondenser and a baffle 15 prevents the loss of steam from the condenser.A pipe 16 connects the surface condenser with a preheatcn 17 while apipe 18 is connected with the boiler which creates steam for the turbine10 so that. water at approximately 212 F. is returned to the boiler forfurther production of steam.

The surface condenser is provided with heads 19 and 20. A conduit 21connects the head 19 with a spray manifold 22. The latter. upon oppositesides of its connection with the conduit 21 is gradually reduced indiameter towards its outer free ends which provides for an equalizationof the pressure when brines or solutions are forced through the nozzles23 of the spray arms 24 so that all of the nozzles 23 will be operatedunder the same pressure and force the solution from said nozzles in amist to the same height over the level 25 of the liquid in the open tank26.

A branch pipe 27 is connected with the supply pipe '21 and suppliesheated brine to 54 and 5g age closedwhile valve 56 is open. "A pipe 57is connected"atone-end with a another spray manifold 28 which extendslongitudinally of a square fiat pond or open tank 29. This tank has aplurality of spray nozzles 30 connected with arms 31, with the armsplaced in groups and provided at spaced intervals along the manifold 28.This manifold is likewise decreased in diametcr from opposite sides ofthe connections 32 so that all of the nozzles will be supplied with apredetermined pressure and that the mist coming from said nozzles willbe projected from the same at substantially the same angle and tosubstantially the same distance frond said nozzles. A return pipe 33 isconnected by means of a pipe 34 with.

a tank 26 and by means of a pipe 35 with tank 29. A. valve 36 controlsthe discharge through pipe 35 while a valve 37 controls the admission ofbrine to the tank 29. A valve 38 controls the; flow of the brine solu-'tion to the tank 26.

The pipe 34 has acheck valve 39 formed in a casing 40, which permits theflow of liquid of the brine from the tank 26 to the condenser 12 butprevents the return of the brine to said tank. It will be seen fromFigure 3 that pipe 34 terminates at 41 adjacent the inclined end wall 42of the tank. Adjacent the end 41 of the pipe 34 is disposed an open end43 of a pipe 44. This pipe is turned upwardly as shown at 45 and isconnected by means of a pipe 46 with a pipe 47. A motor drivenreversible pump 48 is interposed in the line 47 for the purpose whichwill be presently explained. However, when the valve 49 in the supplypipe 50 is closed and valve 51 in pipe 52 is opened the pump may forcebrine intermittently or continuously through pipe 47, pipe 46. and pipe44 into the pipe 34. At this time valves tion 43 is directed towards thepipe 34. The pipe 34 and pipe 64 may be a single pipe.

The channel 62 extends not only transversely of the tank 26 but upwardlythrough a side wall 68 as shown at 69 which is extended at 70 above afloor space 1 which embraces the periphery of theupper open end of thetank 26. The upper free end of the extension 70 is turned downwardly asshown at 72 sothat the crystals which are carried up by the travellingcarrier 73' through the. blades 74 are deposited upon the slides 72whence the crystals may be collected. The carrier 73 extendslongitudinally of the transverse channel 62 and also of the channel 69.A sprocket 7 5 mounted in the inner end of the channel 62 supports thecarrier at that point. Sprockets 76 and 77 maintain the carrier inproper position while a sprocket 78 disposed at any point above thefloor 71 not only serves to support the carrier at this point but alsodrives the carrier.

The bottom of the tank 26 may be provided with a single longitudinalgroove or a plurality of parallel longitudinal grooves 63 separated bywalls 80 which are triangular shaped in cross section, these wallshaving their sides 81 inclined as are the side walls 82 of the tank 26.In each of the longitudinal grooves 63 are disposed travelling carriers83 having fins or scrapers 84 which drag across the bottom of the grooveand are supported by sprockets 85 at the oppo site ends of said grooves.The sprockets 85 are positively driven and are all placed upon the sameshaft 86 which is in turn driven through a chain (not shown) andconnected with the driving mechanism of the sprocket 78 so that allof-the travelling carriers are driven synchronously. As the travellingcarriers 83 are operated in the grooves 63 T 58. while the other end isconnectedto alLcrystallized substances are forced from a T 59 of thepipe 34 so that "fresh brine from pipe 52 or water from pipe 56 may besupplied directly to pipe 34 upon one side of the valve 39. The pipeline 57 and the check valve 39 permit priming of the system.

A pipe 60 has an end 61 terminating within the wall 42 of the tank 26and at the bottom of a transverse channel 62 formed at one end ofthetank 26 and below the level of the channels 63 which extendlongitudinally of the tank.

A pipe 64 extends substantially the entire length of the tank 26 and hasone end in coinn'iunication with pipe 34 and the other end. as shown at66. closed. A slit 67 extends substantially the length of the pipe 64and the brine or solution in the tank 26 is drawn through the slittedportion by the suction in the pipe 34. The connection 34 between pipes34 and 64 is provided with an opening into which the bent portion 45 isinserted so that the open end or nozzle perthe grooves63 into thechannel 62 whence the travellinficarrier-7 3 carries the crystalsoutwardly and depdsitsthem. upon the discharging shelf 72.

The manifolds 22. and 28 aresupported by means of an arrangement shownin. end view in Figure 2 1n WhlCl'l a plurality of.

- manifolds.

Since the brines or solutions are sprayed to the open air it isnecessary to control natural wind currents which will not only atfeetthe deposition of the spray over the pond but will also affect the rateof evaporation. In order to accomplish this control I have provided aplurality of frames 90 arranged along one side of the tank 26andsupported on the floor or platform 71 or the frames may be arrangedentirely around the periphery of said tank. In each of the frames isdisposed a plurality of movable shutters or slats 91 which are connectedtogether by means of cables or rods 92 for operating the shutters sothat the Openings between the same may be increased or decreased. Meansis provided (not shown) for maintaining the shutters in adjustedposition. Each of the shutters is pivotally mounted for rocking movementin the side bars 93 of the frames.

A plurality of frames 95 are disposed above the normal liquid level inthe evaporating tank 26. being supported preferably in downwardlyinclined positions on both sides of the manifold 22. These framesinclude a plurality of pivotally mounted slats 96 which are connectedtogether by a cord or cable 97 so that the slats may be arranged in anyangular relation with respect to the horizontal for checking the fall ofthe spray as it issues from the nozzles 23. It will be noted that theslats 96 are arranged in an overlapping stair-step or cascade efiect sothat the mist starting at the uppermost slat will travel downwardly fromslat to slat and is finally discharged into the tank along the sidewalls. This aids in maintaining the surface of the liquid in the tankfree from agitation whereby the larger crystals are formed. By thealteration of the position of the slats, the cascade effect of theprogression of the brine will be changed into a series of shortdischarges of the brine from each individual slat or the slats may be sopositioned that the mist will fall dircctly through the slats upon thesurface of the liquid so that the amount of agitation caused by thefalling of the brine may be controlled to any degree desired, with aconsequent control of the size of the crystals.

An apron 100 of suitable fabric or the like is draped over the pipe 34upon opposite sides of the slit 67 so that this pipe may be protectedfrom the path of travel of the settling crystals and prevent theformation of the crystals along the pipe and thus prevent the cloggingof the pipe and the slit 67.

In carrying out my process of obtaining crystals the tank 26 is filledwith a predetermined quantity of a solution or brine through the supplypipe 52 and pipe 47 and the solution may be fed into the tank either bygravity or by means of a pump 48 which is operated by an electric motoror any other form of motor suitable for the purpose. At this time valves49 and 53 are closed, while valve 55 is open. A predetermined level ofbrine is maintained in the tank 26 for controlling the size of thecrystals which are formed by the concentration or saturation of thebrine. The pump 94 is then operated and may be driven through operativeconnections with the steam turbine or by means of a motor from thecurrent of the power house in which the steam turbine is located foroperating the generator. This pump promotes the circulation of the brineor solution between the tank 26 and the surface condenser 12. The pumpcreates a suction on pipe 34 and the brine flows through the open end 41of said pipe and where said pipe projects into the tank 26. The flow ofbrine through the end 41 of pipe 34 causes the brine in pipe 64 tolikewise move past the open end 65 of pipe 64 with the fluid passingthrough the slit 67 of said pipe. In order to prevent the formation ofcrystals in the pipes 34: the valves 55, 54 and d9 are maintained closedand valves 51, 53 and 56 are opened and the pump 48 is operated so thatthe solution or brine is pumped through pipe 44, 45 and through the openend 43 and into the pipe 41. This unsaturated brine passing through theipe dissolves or prevents the formation 0t crystals all along the lineand through pipe 34, 33 and through the surface condenser-12 and pipe 21back to pipe 22. The check valve 39 in the casing-40 permits thedischarge of the fluid from the tank 26 but prevents its return.

As the fluids pass through the surface condenser 12 which is connectedwith the steam turbine the solutions absorb heat while passing throughthe'condenser so that the temperature of the brine or solution is raisedslightly above atmospheric temperature and under normal conditions thismay be approximately 10 to 15 degrees. It will be appreciated, however,that due to variations of the temperature at different seasons of theyear the rise in temperature above atmosphere will be considerablygreater than 10 or 15 degrees. It will be appreciated that the raisingof the temperature of water from approximately 80 F. to 212 F. willrequire 122 B. t. u.s while in converting the water to steam and inwhich it is necessary to overcome the cohesion of the molecules. andexternal pressure, 970 B. t. u.s or the heat of vaporization isrequired. It will be seen that a greater percentage of heal units isrequired in converting the water at 212 to steam at 212. However. only158 B. t. u.s are required for raising the temperature of the steam 158.A careful consideration of this condition reveals the fact that 280 B.t. u.s only are required to raise the temperature of the fluid from 80to 370 while 970 B. t. u.s are required for converting the water intosteam at the same temperature. It is an important feature of the presentinvention that the enormous quantity of B. t. u.s which represent thelatent heat of the steam is utilized for raising the temperature of thebrine a predetermined degree so lUU that when the brine is sprayed as'amist into the atmosphere condensation and evaporation take place ata-very rapid rate so that the brine is rapidly concentrated until itreaches saturation when crystals will be formed. Furthermore a vacuum isdrawn on the condenser so that the'pressure within the condenser isapproximately zero absolute. This negative pressure aids in preventingthe lowering of the temperature of of the liquid in the tank 26. It

a the last B. t. u.s bein the condensate so that no energy is wasted byovercomin external pressure. As the brine passes through the surfacecondenser it is heated and the brine is then pumped to pipe 22 which isforced through the arms 24 and through the spray nozzles 23 in the formof a mist, where rapid evaporation takes place before the liquids reachthe level will be ap preciated that this rapid evaporation, due to theenormous quantities of heat units that it absorbs from the condensate,takes place far below the boiling points of the liquids and atatmospheric pressure.

In a power plant which is associated with the tank describedapproximately 230,000 feet of gas per hour produces 160,000 pounds ofsteam and 10,000 K. W. of power. Of the total of 230,000,000 B. t. u.sgenerated in the furnaces 36,000,000 are transformed into power;34,000,000 are lost by radiation, etc, and 160,000,000 B. t. u.s aredissipated in the spray pond at considerable expense, otherwisedissipated to the atmosphere in t 1e spray pond for the concentration ofthe salt brines and from which it will be noted that an enormous savingof energy is had. This latent heat which is ordinarily wasted, isutilized in the manufacture of salt or for the concentration of brineswhich. are obtained in large quantities from any source, but which arelargely obtained in the oil regions from the salt Water which is pumpedwith the oil in the oil wells.

This brine is collected and then carried to the spray pond or tank 26and contains sodium chloride, magnesium and calcium chlorides. When theconcentration of the brine becomes suflicient, crystals of sodiumchloride form and are removed by the drag scrapers 63 and 73 which areoperated si multaneously.

After the bittern reaches a concentration of about 40% magnesium andcalcium chloride, all salt has been deposited and the bittern is removedfor further treatment by standard methods to separate the magnesium fromthe calcium.

By properly regulating the rate of flow of a fresh charge of brinethrough pipe 44 to the discharge pipe 34 not only the level of theliquid in the tank 26 may be maintained constant for controlling thesize of. the crys tals, but the accumulation of crystals in thedischarge line pipe 34 and the return pipe 21 will be prevented. Byvarying the level I of the brine in the tank the size of the c stale iscontrolled since a higher level of brine permits the crystals to travela greater distance through the brine with a consequent enlargement ofthe crystals and vice, versa;

What I claim is:

1. A continuous salts from a solutionhich comprises passing the Solutionin heat inter-changing relationship with a fluid being condensed whilemaintaining a mately zero absolute on the fluid so that latent heatfreed from said fluid upon condensing will be utilized to increase thetemperature of the solution but slightly above atmospheric temperature,converting the heatatmospherethereby warm- .55

ed solution into a mist, in the over a body of the solution, ing theatmosphere with which the spray comes into intimate contact, keeping theatmosphere above its dew point thereby effect: ing continuous and rapidevaporation of moisture from said solution throughout the range oftravel of said mist from the point at which it emanates to the surfaceof the body of the liquid into which it falls.

2. A. continuous process for recovering salts from a'solutionwhich'comprises heating the solution, converting the heated solutionintoa mist in the atmosphere over a body of the solution, thereby warmingthe atmosphere with which the spray comes into intimate contact, keepingthe atmosphere above its dew point thereby effecting. continuous andrapid "evaporation of moisture from said solution throughout the rangeof travel of said mist from the point at which it emanates to thesurface of the body of the liquid into which it falls.

A continuous process for recovering salts from a solution whichcomprises pass ing the solution in heat interchanging relationship witha fluid being condensed, thereby utilizing the latent heat freed fromsaid fluid upon condensing to increase the temperature of the brine toapproximately the process for recovering pressure of approxitemperatureof the condensate, converting the heated solution into a mist in theatmosphere over a body of the solution, thereby warming the. atmospherewith which the spray comes into intimate contact, keeping the atmosphereabove its dew point thereby effecting a continuous and rapid evaporationof moisture from said solution throughout the range of travel of saidmist from the point at which it emanates to the surface of the body ofthe solution into which it falls,

brine and for maintaining a predetermined level of the body of thesolution.

a. A continuous process for recovering salts from a solution whichcomprises heating the solution, converting the heated solution into amist in the atmosphere over a body of the solution, thereby warming theatmosphere with which the spray comes into intimate contact, keeping theatmosphere above its dew point thereby eflecting continuous and rapidevaporation of moisture from said solution and interrupting the fall ofthe brine after misting for checking the velocity of the mist to controlthe size of the crystals formed.

5. A continuous process for recovering salt from brine which comprisesheating the brine, converting the heated brine into a mist over a bddyof the solution, exposed to the atmosphere, thereby reducing thetemperature of the brine to approximately the dew point so that moistureis removed between points where the mist is created and the level of thebrine body with the consequent concentration of the brine, spreading thebrine after misting over a surface above the level of the body of thebrine and varying the angular position of the surface for regulating thesize of the crystals formed.

6. A continuous process for recovering salts from a solution whichcomprises passing the solution in heat interchanging relationship with afluid being condensed in a surface condenser, thereby utilizing thelatent heat freed from said fluid upon condensing to increase thetemperature of the solution to approximately the temperature of thecondensate, converting the heated solution into a mist in the atmosphereabove a body of the solution, keeping the atmosphere above its dew pointthereby effecting the continuous and rapid evaporation of moisture fromsaid solution throughout the range of travel of said mist from the pointat which it emanates to the surface of the body of the solution intowhich it falls, interrupting the fall of the brine after misting forcontrolling the size of the crystals formed in the body of the solutionand then removing the crystals formed at points along the center of thebody of the solution.

7. A continuous process for recovering salts from a solution whichcomprises heating the solution, converting the heated solution into amistcin the atmosphere ever a body of the solution, thereby warming theatmosphere with which the mist comes into intimate contact, keeping theatmosphere above its dew point thereby effecting continuous and rapidevaporation of moisture from said solution throughout the range oftravel of said mist from the point at which it emanates to the surfaceof the body of the solution into which it falls, and

directing the crystals formed by the concentration of the brine in thebody of the solution along lines running longitudinally of the body ofthe solution.

8. A continuous process for recovering salts from a brine solution whichcomprises passing the solution in heat interchanging relationship with afluid being condensed while maintaining the pressure on the fluid atapproximately zero absolute scale so that the latent heat freed fromsaid fluid upon condensing will be utilized to increase the temperatureof the brine to approximately the temperature of the condensate,convcrtin g the heated solution into a mist, in the at mosphcre over abody of the solution thereby warming the atmosphere with which the spraycomes into intimate contact, keeping the atmosphere above its dew pointthereby eflecting continuous and rapid evaporation of moisture from saidsolution throughout the range of travel oi? said mist from the point atwhich it emanates to the surface of the body of the solution into whichit falls, returning the concentrated brine to heat exchanging relationwith the fluid for the absorption of heat while adding :1 limited chargeof w Ll OI brine to the concentratcd brine during the return of theconcentrated brine for causing the dissolving of salt crystals along thepath of the brine and for maintaining a predetermined level of solutionin the body.

9. A continuous process for recovering salts from a solution whichcomprises heating the solution, (ainverting the heated solution into amist in the atmosphere ever a body of the solution, thereby warming theatmosphere with which the spray comes into intimate contact, keeping theatmosphere above its dew point thereby effecting continuons and rapidevaporation of moisture from said solution tlnfongbont the range oftravel oi said mist from the point at which it emanates to the surface.of the body of the solution into which it falls, withdrawing theconcentrated brine from the tank in a continuous thin sheet, heating thewithdrawn brine then returning the heated brine in a mist above thesurface of the body of the solution.

10. A continuous process for recovering salt from brine which comprisesheating the brine, converting the heated brine into a mist over a bodyof the brine exposed to the atmosphere thereby reducing the temperatureof the brine to approximately the dew point so that moisture is removedbetween the points where the mist is created and the level of the bodyof the brine with the consequent concentration of the brine, wi hdrawingthe concentrated brine from the tank in a continuous thin sheet, addinga limited charge of unconcentrated brine to lUlJ brine and misting theheated brine over the body of the brine.

11. A continuous process for recovering salt from brine which comprisesheating the brine, converting the heated brine into a mist over a bodyof brine exposedto the atmosphere thereby reducing the temperature ofthe misted brine to approximately the dew point so that moisture isremoved between points where the mist is created and the level of thebrine in the body of said brine with the consequent concentration of thebrine and controlling the size and shape of the ranules of salt whichare formed in the liody of the brine by varying the pathof the fall ofthe mist to the body of the brine.

12. A continuous process for recovering salt from brine which comprisesheating the brine, converting the heated brine into a mist over a bodyof the brine exposed to the atmosphere thereby reducing the temperatureof the misted brine to approximately the dew point so that moisture isremoved between points where the mistis created and thelevel of thebrine with the consequent concentration of the brine, controlling thesize-of the c stals of the salt by regulating the depth 0 the body ofthe brine by-a charge of fresh brine admitted to the body of the brine.

13. A continuous process for recovering salt from brine which comprisesmaintaining a fluid adapted to be condensed with the pressure on saidfluid being approximately zero absolute scale, passing the brine as acooling agent'in heat exchanging relation with the fluid and utilizingthe latent heat freed from the fluid for raising the temperature of thebrine, spraying the heated brine in the form of a mist over a body ofthe brine while exposing the mist to the atmosphere so that apredetermined quantity of the moisture is eliminated and the brine isthus concentrated with a consequent lowering of the temperature of saidbrine.

14. A continuous process for recovering salts from a brine whichcomprises heating the brine slightly above atmospheric temperature,converting the heated brine into a mist over a body of the brine exposedto the atmosphere, thereby reducing the temperature of the brine toapproximately the dew point with the consequent evaporation of part ofthe water of the brine, withdrawing the concentrated brine from the bodyof the brine while adding afresh charge of brine to the withdrawn brinefor regulating the level of the brine in the body of the brine, heatingthe mixture of the withdrawn brine and the fresh charge of brine, thenmisting the heated brine over the body of the brine,

the addition of a charge of unconcentrated brine preventing theformation of crystals during withdrawal of the brine from the body ofthe brine;

15. In a process for recovering salts from a solution, the steps whichcomprise heating the solution above the dew point temperature of theatmosphere, co verting the heated solution into a mist in t e atmosphereover a body of the solution and keeping the atmosphere above its dewpoint by controlling the amount of air coming into contact with the mistto insure rapid evaporation of moisture from the solution throughout therange of travel of said mist from the point at which it emanates to thesurface of the body of the solution into which it falls.

16. In a process for recovering salts from a solution, the steps whichcomprise passing the solution in heat-interchanging relationship withafluid being condensed so that normally wasted heat freed from said fluidupon condensing will be utilized to increase the temperature of thesolution above atmospheric dew point temperature, converting the heatedsolution into finely divided spray form in the atmosphere over abody ofthe solution, thereby warming the atmosphere with which the spray comesinto intimate contact, controlling the temperature of the heated brineand the supply of air coming into contact with said spray to keep saidair above its dew point, therebyeflecting rapid and continuousevaporation of moisture from said solution throughout the range oftravel of said spray from the point at which it emanates to the surfaceof the body of the solution into which it falls.

17. In a process for recovering a salt from a solution thereof, thesteps which comprise. passing a less than saturated solution of the saltin heat-interchanging-relationship with a fluid being condensed, wherebynormally waste latent heat freed from said fluid wi'll be utilized toincrease the temperature of the solution above the dew point temperatureof the atmosphere, discharging the heated SOllltion at a point above thebody of the solution in such a manner as to expose a large surface areaof the discharge solution to evaporation in the atmosphere andcontrolling the amount of atmospheric air coming into contact with thedischarged solution and the temperature of said heated solution to keepthe temperature of said air above its dew point, thereby effecting rapidand continuous evaporation of moisture from said solution throughout therange of travel of said solution from its point of discharge to thesurface of the body of the solution into which it falls.

o'rro v. MARTI

